The invention concerns a filter insert piece comprising a pleated filter element, comprising a first pleated section with parallel arranged pleats and a second pleated section with parallel arranged pleats, wherein the first and the second pleated sections have different inflow sides in the filter element and the pleated sections adjoin a common clean chamber.
EP 0 973 597 B1 discloses a filter insert piece that comprises for fluid filtration a filter element which has a fir tree-like structure. The filter element is assembled of two halves and encloses a clean chamber. The two halves each are flowed through from the exterior to the interior, wherein the purified fluid is collected in the inwardly positioned clean chamber and discharged from the latter.
U.S. Pat. No. 5,043,000 A discloses an air filter element that is cylindrically embodied and is comprised of several filter segments distributed about the circumference and each configured as a pleated filter with parallel arranged folds. In the interior of the filter element, an axially extending clean chamber for all filter segments is provided from which the purified fluid is axially discharged.